LiveTV & ffmpeg MVP playback stops

[pvruser]

I'm using an MVP with the mvpmc dongle. My problem is that i can play most files just fine but when it comes to livetv or a recording in progress the playback will stop once i reach the point where i pressed "play" in real time.

what i'm assuming is that ffmpeg will only transcode up to the point where i started playing back the recording and then dies. is there anything i can change in the ffmpeg transcoding settings to assure it will "follow" the live recording and convert it till the end?

Thanks!

[Bobins]

I think the answer is no.

I assume you're not recording in mpeg format (ATI or Cyberlink mux) so need to transcode for the MVP?

When the transcode starts, it will run faster than the rate at which you are watching the output and also faster than the rate at which the programme is being recorded. It has no knowledge of when it's going to catch up to the end of file for the file which is being recorded. When it does hit the end-of-file, it will terminate the transcode hence what you experience.

I don't know of any way of telling ffmpeg to pause or slowdown it's transcode so it won't reach the end-fo-file while the file is still growing.

The way round this is to record in mpeg so you don't need to transcode.

[mvallevand]

Unfortunately in North America most digital broadcast use AC3 audio and mux'ing is not an option. I know zehd has been pushing the ATI mux too, but AC3 just won't work well enough on the mvpmc dongle for it to be useful.

Martin

[pvruser]

i'm recording tv with the ATI mux so live TV should be OK but some of my stations are 720p or 1080i in addition to 480i (SD). because of that i have to set option MvpTranscodeAllVideo true and that will also force ffmpeg to run for SD. so if a recording is half way and i'm watching it, it stops when ffmpeg reaches the end.

it's too bad there is no "stream" option just like ccextractor has the -s option:

-s --stream [secs]: Consider the file as a continuous stream that is
growing as ccextractor processes it, so don't try
to figure out its size and don't terminate processing
when reaching the current end (i.e. wait for more
data to arrive). If the optional parameter secs is
present, it means the number of seconds without any
new data after which ccextractor should exit. Use
this parameter if you want to process a live stream
but not kill ccextractor externally.
Note: If -s is used then only one input file is
allowed.

as you can see such an option with -s 10 would wait 10 seconds before ending the transcoding but will sleep and transcode as long as the livetv file is growing. maybe it's possible to "fool" ffmpeg to behave like this but i didnt see a way to do it.

[Bobins]

I'm impressed if you can watch any 720p or 1080i "Live TV" on the MVP with on-the-fly transcoding. My new Quad processor machine couldn't transcode fast enough for HD to play anything more than a couple of seconds before playback reached the end of the temporary transcode file and the playback terminates.